//
//  Stack.m
//  SlashEM
//
//  Created by dirk on 1/3/10.
//  Copyright 2010 Dirk Zimmermann. All rights reserved.
//

//  This file is part of Slash'EM.
//
//  Slash'EM is free software: you can redistribute it and/or modify
//  it under the terms of the GNU General Public License as published by
//  the Free Software Foundation, version 2 of the License only.
//
//  Slash'EM is distributed in the hope that it will be useful,
//  but WITHOUT ANY WARRANTY; without even the implied warranty of
//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
//  GNU General Public License for more details.
//
//  You should have received a copy of the GNU General Public License
//  along with Slash'EM.  If not, see <http://www.gnu.org/licenses/>.

#import "ZStack.h"

@implementation ZStack

- (id)init {
	if (self = [super init]) {
		objects = [[NSMutableArray alloc] init];
	}
	return self;
}

- (void)push:(id)obj {
	[objects addObject:obj];
}

- (id)pop {
	id obj = [objects lastObject];
	[objects removeLastObject];
	return obj;
}

- (id)peek {
	return [objects lastObject];
}

- (id)top {
	return [self peek];
}

- (int)count {
	return objects.count;
}

- (id)bottom {
	if (objects.count) {
		return [objects objectAtIndex:0];
	} else {
		return nil;
	}
}

- (void) dealloc {
	[objects release];
	[super dealloc];
}

@end
